Problem Mindcrack server causing high CPU/RAM usage? (Reason found)

[Humbug911]

My dedicated servers hardware

Xeon 1240 3.4Ghz 8 cores.

16GB RAM
And this Mindcrack server is using 80-100% cpu usage, this does not feel normal for it to do?
What average usage in RAM and CPU should i count on?
Currently 14 players online.

What could be wrong with this server?

Can you help?

Its causing issues with the one other server im hosting, a normal bukkit server, only using like 15-20% normally and only 1-10 users.
Server is only used for these 2 servers so far so :/


Possible reason found

I can add that i found reason for my problem...
As many people sad, Minecraft/Java cant handle dual core/quad core very good.
because im using -XXarallelGCThreads=24 at the moment(dual CPUs, yes i got 24 cores ) and it uses 2 cores, i tried 2-4-6-8 without success. no improvement.
Here is a note from my host who spoke about and explained, might be good for people to read

“However there is lots of "user" time on cpu7 (99,7%) and some on cpu16
and 21, and almost none on other cores. Judging from 'top' results (top
processes) you provided, your java application (probably minecraft
server you mentioned) can't utilize lots of CPU cores/threads - it fills
out single core, and uses some power of two more and that's it. It can't
utilize multithreaded processing power these CPUs can offer.

Probably that's why on E3-1270 CPU your application runs better - even
though on E3-1270 you have less cores available, single core speed is
higher. And your application seems unable to scale out on multiple
CPUs/cores - it needs as fast as possible single core.​

Thats why my server with E3-1270, which has a 3.50ghz clock rate worked better, and this a lot worse.
Hope it explains it for most people ​

 

[Cavious]

Trust me when I say you're not the only one with this issue. I run the TeslaCraft-MC servers and I too am running into crashes, high use of memory, and block lag. I had the server up for one week with ZERO issues and all the sudden now its crashing every few hours.

 

[glasspelican]

you can try launching the server with this
please note that the command needs to be on a single line, it is spaced out so I can read it.
also make sure you set your server jar name correctly
I dont mean to state anything you man already know but these are problems I have had with people before
Hope it helps.
Also the current version of MFFS is known to eat cpu

java -server -Xincgc -Xmx6G -Xms2G -Xmn1G -XX:NewRatio=2
-XX:CMSFullGCsBeforeCompaction=1 -XX:SoftRefLRUPolicyMSPerMB=2048
-XX:+CMSParallelRemarkEnabled -XX:+UseParNewGC -XX:+DisableExplicitGC -Xnoclassgc
-XX:+UseFastAccessorMethods -XX:CMSInitiatingOccupancyFraction=90
-XX:+UseConcMarkSweepGC -XX:UseSSE=4 -XX:+UseCMSCompactAtFullCollection
-XX:ParallelGCThreads=4 -XX:+AggressiveOpts
-XX:+UseLargePages -XX:ReservedCodeCacheSize=1G
-cp server_jar_name_here.jar -jar server_jar_name_here.jar

edit: the above code is tuned to the OPs system your computer may vary

 

[Humbug911]

bump! reason found at least... might be good to know for people in the same situation